CHARACTERS OF THE ORDER HAPLOMI. 259 



poral from the clavicle ; postclavicle a simple ovate scale of 

 bone ; hypercoracoid foramen entirely enclosed by the hyper- 

 coracoid ; actinosts small, deeper than long, no opening between 

 them, two on each the hypercorcoid and the hypocoracoid ; pel- 

 vic bones each with a spur extending inward, one of which over- 

 lies the other ; upper end of shoulder girdle joined to bassioc- 

 cipital by a long ligament ; l large projecting parapopyhyses 

 present on all abdominal vertebrae ; the caudal supporting haemal 

 spines ankylosed to their centra ; the posterior vertebrae not 

 tilted up ; vent normal in position. 



FAMILY PCECILHDyE. 

 Subfamily FUNDULIN.E. 



Characters as indicated by Fiindnlus siinilis? 



Interorbital septum double, its sides widely separated through- 

 out ; no myodome ; parasphenoid sending a lateral process up to 

 alisphenoid ; supraoccipital expanded latterly on top in a thin 

 horizontal wing ; epiotic developed backward in a long thin 

 process as in the genus Mugil ; occipital condyle partly formed by 

 exoccipitals ; prefrontals not meeting at the median line ; basi- 

 sphenoid and opisthotic absent ; mandible normal ; premaxillaries 

 normally curved ; posttemporal a simple bone with no indication 

 of a lower fork, normally attached to epiotic ; three superior 

 pharyngeals.on each side joined (not ankylosed) to form an ovate 

 plate, covered with molar-like teeth near middle of bone, which 

 change to small blunt conical teeth near outer edges ; lower 

 pharyngeals joined to each other by deeply dentate and inter- 

 locked suture, 3 together forming a triangular bone with concave 



1 The ligament runs from the middle of the outer edge of the basioccipital to the 

 upper end of the clavicle in Pcedlia and Cyprinodon, equally to the inner surface of 

 the supraclavicle and the posttemporal in P'unduliis. 



2 Gainbusia (as exhibited in species nobilis) agrees with Fnndulus in character of 

 superior pharyngeals and unforked posttemporal but in the condition of the occipital 

 condyle resembles Pixcilia. 



3 The lower pharyngeals of the following species of /<;/<//,? have been exam- 

 ined : siminolis, catenatus, majalis, stellifer, diaphamts, nottii, notaius, sciadicus, 

 rathbuni, zebrinus and heteroclitus, and a nearly uniform gradation found from the 

 first, where the pharyngeals were joined by simple suture, together forming a triangu- 

 lar plate, to the last, where they were elongate and attached only at their anterior 

 ends, diverging posteriorly. They were all joined more or less loosely. None were 

 attached by dentate suture, as in similis. The gradation from one to another was 

 in about in the order here given. 



